JPH11124897A - Suction water tank for pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a strong preliminary vortex flow in a preliminary vortex part to increase the suction efficiency of solid materials such as scum or sand and prevent these materials from remaining even when a large quantity of scum accumulates and floats. SOLUTION: When the water level in a water tank body 2 decreases from an operation start water level HWL down to a vortex flow start water level LWL by the operation of a pump P1 or another pump P2, the water level is detected by a level detector 17 and a vortex flow-generating valve 19 interposed in a branch pipe 15 is opened on the basis of the detected water level. In this way, a part of the pressurized water discharged to the delivery pipes 12A or 12B of the pumps P1, P2 is ejected from a vortex flow-generating nozzle 16 through a convergent delivery pipe 13 and the branch pipe 15. A strong vortex flow is generated in the water tank body 2 by the ejecting pressure water and the accumulating and floating scum on the water level is rotated and agitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction water tank for a pump that functions as a manhole or a pump well in a sewage relay pumping station, a drainage pumping station, or the like.

[0002]

2. Description of the Related Art A conventional suction water tank of a pump functioning as a manhole or a pump well in a sewage relay pumping station is shown in FIG.
As shown in FIG. 9 and FIG. 9, a pump P1 and a pump P1,
The pedestals 4 and 4 for fixing the discharge bend 3 of P2 are formed, and the drop holes 6 for inserting the respective suction ports 5 of the pumps P1 and P2 are formed at the positions immediately upstream of the pedestals 4 and 4. .

[0003] In the suction water tank of a pump having such a structure,
The two pumps P1 and P2 are operated alternately. For example, when the pump P1 is operated, sewage in the water tank main body 2 is sucked up from the suction port 5 of the pump P1, and when the pump P2 is operated, water in the pump well 2 is discharged from the suction port 5 of the pump P2. Sucked up from.

However, in the suction tank of the conventional pump described above, it is difficult to discharge all floating scum and sediment by the pumps P1 and P2 smoothly. Have. This can be said to be the case in FIG. 9 where the bottom member 2A of the water tank main body 2 is a so-called "solid bottom" and does not have the drop hole 6 and the long suction port 5.

Therefore, as shown in FIGS. 5 to 7, pre-swirl sections 8A, 8 into which suction ports 5 of pumps P1, P2 are inserted.
B and water flowing from the sewage inflow pipe 1 into the water tank main body 2 are guided to the pre-swirl section 8A in a tangential direction or a direction close to the pre-swirl section 8A, and a rotation direction R1 of a pump impeller (not shown) in the pre-swirl section 8A. To the inflow path 9 and the pre-swirl section 8B for generating a pre-swirl flow swirling in the same direction R2 as the tangential direction or a direction close thereto, and the rotation direction of a pump impeller (not shown) in the pre-swirl section 8B. It is conceivable to install a pre-swirl tank 7 made of reinforced plastic (FRP) provided with an inflow passage 10 for generating a pre-swirl flow swirling in the same direction R2 as R1 on the upper surface of the bottom member 2A.

[0006] By installing the pre-swirl tank 7 and operating the pump P1 or P2, the water in the water tank main body 2 passes through the inflow passage 9 or the inflow passage 10, and the pre-swirl portion 8A,
8B, and pre-rotates in the pre-rotation portions 8A and 8B in the same direction R2 as the rotation direction R1 of the pump impeller. Therefore, the sewage is efficiently and smoothly sucked from the entire circumference of the suction port 5 of the pump P1 or P2. In addition, solid matter such as sand or scum mixed in the sewage is pump P1.
Alternatively, they are collected just below the suction port 5 of P2 and discharged together with the water, so that these remain in the pre-swirl sections 8A and 8B.
The disadvantages of deposition can be eliminated.

However, when the pump P1 or P2 is operated, the water level in the water tank main body 2 is changed to the pump operation start water level HW.
L, the pre-swirling flow is generated in the pre-swirling unit 8A or 8B after the pre-swirling flow has decreased to near the upper end level LWL1 of the pre-swirling tank 7, but the water level in the water tank main body 2 is at the level L
In a region exceeding WL1, a strong swirling flow does not occur in the water tank main body 2. For this reason, the scum deposited and floating on the water surface cannot be swirled and agitated. When the scum drops to the level LWL1 together with the water surface without turning, the pre-swirl section 8A or 8B Inside the vehicle. Therefore, when a large amount of scum is accumulated and suspended, the power of the pre-swirling flow in the pre-swirling units 8A and 8B is reduced,
There is a possibility that the efficiency of suction of solids such as sand mixed in scum and sewage by the pump P1 or P2 may be reduced.

[0008]

That is, in the suction water tank of the conventional pump, when a large amount of scum is accumulated and suspended, the power of the pre-swirling flow in the pre-swirling section is reduced, and the scum and the scum generated by the pump are reduced. There is a risk that the suction efficiency of solids such as sand mixed in the sewage will be reduced, and these will remain in the pre-swirl section. Therefore, the present invention contributes to the generation of a strong pre-swirling flow in the pre-swirling unit even when a large amount of scum is accumulated and floated, and the scum generated by the pump and sand mixed in the sewage are reduced. An object of the present invention is to provide a pump suction water tank that can prevent solids from remaining in a pre-swirl section by improving the suction efficiency of solids.

[0009]

In order to achieve the above object, a suction water tank of a pump according to the present invention has at least one space for inserting a suction port of the pump into a bottom of a water tank body to which an inflow passage is connected. A swirling part, and a pre-swirl that guides water flowing into the water tank body from the inflow water channel to the pre-swirl part in a tangential direction or a direction close thereto, and turns in the pre-swirl part in the same direction as the rotation direction of the pump impeller. A pre-swirl tank provided with an inflow passage for generating a flow, a branch pipe connected to a discharge pipe of the pump, and a swirl flow generating nozzle provided at the tip of the branch pipe, At a swirl flow generating water level that is deviated to the upper level side of the pre-swirling tank from an intermediate level between the upper end level of the pump and the operation start water level of the pump, and is inclined slightly downward from the horizontal in the same direction as the rotation direction of the pump impeller. And the pump A water level detecting means for detecting an operation start water level and a swirl flow generation water level is provided, and when the water level of the water tank body is reduced from the pump operation start water level to the swirl flow generation water level by the operation of the pump, the swirl flow generation water level is detected. A swirling flow generating valve which opens for a predetermined time based on the detection of the water level detecting means is interposed in the branch pipe.

According to the present invention, when the water level in the water tank main body decreases from the pump operation start water level to the swirling flow generation water level by the operation of the pump, the water level is detected by the water level detection means, and the water level is branched based on the detection of the water level. The swirling flow generating valve interposed in the pipe opens. Thereby, a part of the pressure water discharged to the discharge pipe of the pump passes through the branch pipe and is jetted from the swirling flow generating nozzle provided at the tip of the branch pipe. Since the swirling flow generating nozzle is installed to be inclined slightly below horizontal in the same direction as the rotation direction of the pump impeller, the water level in the water tank main body drops from the swirling flow generating water level to the upper end level of the pre-swirl tank. During this operation, a strong swirling flow is generated in the water in the water tank main body by the pressure water ejected from the swirling flow generating nozzle, and the scum deposited and suspended on the water surface can be swirled and stirred. By continuing the operation of the pump, after the water level in the water tank main body has dropped to near the upper end level of the pre-swirl tank, the water flows into the pre-swirl section through the inflow path, and the pump impeller Pre-turn in the same direction as the rotation direction. For this reason, suction can be efficiently and smoothly performed from the entire circumference of the suction port of the pump. In addition, since solids such as sand mixed in the water can be collected directly below the suction port of the pump, they can be easily discharged together with the water, and solids such as settling sand remain and accumulate in the pre-swirl section. Can be prevented. That is, the swirling flow generated by the pressure water ejected from the swirling flow generating nozzle can be guided to the pre-swirling unit, thereby contributing to the generation of a strong pre-swirling flow in the pre-swirling unit, and the scum and waste water generated by the pump are It is possible to improve the efficiency of sucking solid matter such as sand mixed in the water. Further, even when a large amount of scum is accumulated and floated, the scum can be swirled and agitated by the swirling flow and introduced into the pre-swirl section, so that the scum does not reduce the power of the pre-swirl flow.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view, and FIG. 2 is A in FIG.
FIG. 3 is a sectional view taken along line BB of FIG. 1. The same or corresponding parts as those of the comparative example of FIGS. 5 to 7 and the conventional examples of FIGS. 8 and 9 are denoted by the same reference numerals. 1 to 3, a pre-swirl tank 7 made of reinforced plastic (FRP) is installed on a bottom member 2A of a concrete water tank body 2 to which a sewage inflow pipe 1 is connected. The pre-swirl tank 7 is provided with pre-swirl sections 8A and 8B for inserting the suction ports 5 of the pumps P1 and P2, and water flowing from the sewage inflow pipe 1 into the water tank main body 2 is tangential to or close to the pre-swirl section 8A. Tangentially to the inflow path 9 and the pre-swirl section 8B for generating a pre-swirl flow that guides the pre-swirl flow in the same direction R2 as the rotation direction R1 of the pump impeller (not shown) in the pre-swirl section 8A. In the close direction, and the same direction R2 as the rotation direction R1 of the pump impeller (not shown) in the pre-rotation part BA.
And an inflow path 10 for generating a pre-swirl flow turning.

The pre-swirl unit 8A and the pre-swirl unit 8B in the pre-swirl tank 7 guide the water of the pre-swirl unit 8A or 8B on the other side in a tangential direction or a direction close thereto, so that the pre-swirl units 8B and 8B.
In A, the bottom portions are communicated with each other by a headrace channel 11 that generates a pre-swirl flow that swirls in the same direction R2 as the rotation direction R1 of the pump impeller (not shown). This headrace channel 1
Numeral 1 is constituted by a culvert type headrace upper part.

On the other hand, the discharge pipes 12A of the pumps P1 and P2,
The upper end of 12B is connected to the horizontal discharge pipe 13. One end of the collective discharge pipe 13 extends to the outside through the water tank main body 2 and is connected to a drain pipe 14, and the other end of the collective discharge pipe 13 has a discharge pipe 12 inside the water tank main body 2.
A, 12B and branch pipe 1 smaller in diameter than collective discharge pipe 13
5 is connected. The branch pipe 15 extends downward along the inner surface of the water tank main body 2, and a swirling flow generating nozzle 16 is provided at a tip thereof.

The swirling flow generating nozzle 16 is provided at the upper end level LWL1 of the pre-swirl tank 7 and at the operation start water level H of the pumps P1 and P2.
In the same direction as the rotation direction R1 of the pump impeller, it is installed to be inclined slightly below horizontal near the swirl flow generation water level LWL which is biased toward the upper end level LWL1 side of the pre-swirl tank 7 from the middle of the pre-swirl tank 7. The pump operation start water level HWL and the swirl flow generation water level LWL1 are detected by the water level detection means 17. The water level detecting means 17 is turned on by the vertical movement of the float.
A float switch 17A for detecting an operation start water level HWL of the pump;
A float 17B for detecting the swirling flow generation water level LWL1, a float 17C for detecting the abnormally high water level HHWL, and a float 17D for detecting the upper end level LWL1 of the pre-swirling tank 7.
The water level detection signal detected by the floats 17A to 17D is input to the control means 18. The control means 18 alternately outputs an operation start signal to the pumps P1 and P2 based on the detection signal input from the float 17A, and the turning provided in the branch pipe 15 based on the detection signal input from the float 17B. A valve opening signal is output to the flow generating valve 19. The pumps P1 and P2 simultaneously output an operation start signal based on the detection signal input from the float 17C, and the pumps P1 and P2 operating after a predetermined time elapse based on the detection signal input from the float 17D.
Output the operation stop signal. The water level detecting means 17 is not limited to only the float switch,
Other water gauges may be used.

In the above configuration, when sewage flows into the water tank main body 2 from the sewage inflow pipe 1 and the water level rises to the pump operation start water level HWL, the water level HWL is detected by the float 17A of the water level detection means 17, The detected water level detection signal is input to the control means 18. Control means 18
Outputs an operation start signal to the pump P1 or P2 based on the detection signal input from the float 17A. By operating the pump P1 or P2, sewage in the water tank main body 2 is collected from the discharge pipe 12A or 12B to the collecting pipe 13, and is drained through the drain pipe 14. When the water level falls to the swirling flow generation water level LWL, the water level LWL is detected by the float 17B of the water level detection means 17, and the detected water level detection signal is input to the control means 18. Control means 18
Outputs a valve opening signal to the swirling flow generating valve 19 provided in the branch pipe 15 based on the detection signal input from the float 17B to open the swirling flow generating valve 19.

When the swirling flow generating valve 19 is opened, a part of the pressure water discharged to the discharge pipe 12A or 12B of the operating pump P1 or P2 pump passes through the branch pipe 15 and the branch pipe 15 Swirling flow generating nozzle 16 provided at the tip of
Erupts from Since the swirling flow generating nozzle 16 is installed so as to be slightly downward from horizontal in the same direction R3 as the rotation direction R1 of the pump impeller, the water level in the water tank main body 2 is changed from the swirling flow generating water level LWL to the pre-swirl tank. Top level LW
While the pressure is lowered to L1, the swirling flow generating nozzle 16 generates a strong swirling flow in the water in the water tank main body 2 by the pressurized water, so that the scum accumulated and floated on the water surface can be swirled and stirred.

By continuing the operation of the pump P1 or P2, the water level in the water tank main body 2 becomes the upper end level L of the pre-rotation tank 7.
After lowering near WL1, it flows into the pre-swirl section 8A or 8B through the inflow path 9 or the inflow path 10, and in the pre-swirl sections 8A, 8B in the same direction R2 as the rotation direction R1 of the pump impeller. Make a pre-turn. For this reason, suction can be efficiently and smoothly performed from the entire circumference of the suction port 5 of the pump. In addition, since solid matter such as sand mixed in the water can be collected directly below the suction port 5 of the pump, the solid matter can be easily discharged together with the water, and solid matter such as sedimentation in the pre-rotation part 8A or 8B. Objects can be prevented from remaining and accumulating.

That is, since the swirling flow generated by the pressure water jetted from the swirling flow generating nozzle 16 can be guided to the pre-swirling units 8A or 8B, a strong pre-swirling flow is generated in the pre-swirling units 8A and 8B. Pump P
It is possible to improve the efficiency of sucking solids such as sand mixed in scum and wastewater by 1 or P2. Also, even if a large amount of scum is floating,
The scum is swirled and agitated by the swirling flow to form a pre-swirl unit 8.
A and 8B can be introduced, so that the scum does not reduce the power of the pre-swirling flow. Further, since the jet of the pressurized water from the swirling flow generating nozzle 16 is performed in a state where the water level in the water tank main body 2 is reduced to the swirling flow generating water level LWL and the water amount is relatively low and the water amount is small, a large swirling stirring effect is obtained. And discharge pipes 12A, 12B
Further, since the branch pipe 15 having a smaller diameter than the collective discharge pipe 13 is used, the pumping loss caused by the pump P1 or P2 when the swirling flow generating valve 19 is opened can be reduced.

By continuing the operation of the pump P1 or P2,
The water level in the water tank main body 2 is the upper end level LWL1 of the pre-rotation tank 7.
When the water level LWL1 drops to the water level detection means 17
And the detected water level detection signal is input to the control means 18. The control means 18 operates after a lapse of a predetermined time based on the detection signal input from the float 17D, that is, when the water level in the pre-swirling units 8A and 8B drops to or near the level of the suction port 5 of the pump. An operation stop signal is output to the pump P1 or P2 to stop the operation of the pumps P1 and P2.

On the other hand, the operation of the pump P1 or P2 causes the water level in the water tank body 2 to rise to the upper end level LW of the pre-rotation tank 7.
When it becomes lower than L1, the water and the sand and scum in the pre-swirl section 8A or 8B on the pump operation side are sucked up by the operated pump P1 or P2, and the water and the sediment in the pre-swirl section on the pump stop side are removed. The scum and the like are introduced into the pre-swirl section on the pump operation side through the open type water channel 11, and are sucked up by the operated pump P1 or P2. Sewage and scum introduced from the stop-side pre-swirl section through the open-type headrace channel 11 to the driving-side pre-swirl section have the same direction R2 as the rotation direction R1 of the pump impeller in the driving-side pre-swirl section. , The suction can be efficiently performed smoothly from the entire circumference of the suction port 5 of the pump P1 or P2. In particular, solids such as sand, scum, and the like can be reliably discharged, and can be prevented from remaining and accumulating in the stop-side pre-rotation portion 8A or 8B.

In the above embodiment, the two pre-swirl sections 8
A and 8B are provided and two pumps P1 and P2 are used, but one pre-swirl unit is provided, and a configuration using one pump or three or more pre-swirl units is provided and three or more pre-swirl units are provided. A configuration using a pump may be used. In addition, the pre-swirl tank 7 made of reinforced plastic (FRP) is attached to the bottom member 2A of the water tank body 2.
Instead of the configuration installed on the upper surface of the above, a configuration in which pre-swirl portions 8A, 8B, inflow passages 9, 10 and water conduit 11 and the like are formed on a bottom member 2A made of concrete may be used. further,
The culvert-type headrace channel 11 is used, but the upper part is open.
The open channel 11 may be used. Open type waterway 1
1 is that, since clogging due to solids such as sand and scum can be promptly confirmed by visual observation, clogging can be immediately eliminated, and since the structure and assembly are simple, the culvert It is more advantageous than the mold headrace 11.

Although the description has been given of the cylindrical manhole type water tank main body 2, a square pump well type water tank main body 2 installed at the downstream end of the inflow passage 1 may be used as shown in FIG. In this case, three inflow paths 9, 9 are provided in the pre-rotation section 8A.
A, 9B, three inflow paths 10, 10
A and 10B can be provided.

[0023]

As described above, according to the present invention, when the water level in the water tank main body decreases to the level at which the swirl flow is generated by the operation of the pump, a part of the pressure water discharged to the discharge pipe of the pump forms a branch pipe. When the water level in the water tank body drops from the swirl flow generation water level to the top level of the pre-swirling tank, a strong swirling flow is generated in the water inside the water tank body, and the water is deposited and suspended on the water surface. The rotating scum can be agitated. Therefore, the swirling flow can be guided to the pre-swirl unit, which contributes to the generation of a strong pre-swirl flow in the pre-swirl unit, thereby reducing scum generated by the pump and solids such as sand mixed in the sewage. The suction efficiency can be improved. Further, even when a large amount of scum is accumulated and floated, the scum can be swirled and agitated by the swirling flow and introduced into the pre-swirl section, so that the scum does not reduce the power of the pre-swirl flow. Further, since the jet of the pressure water from the swirling flow generating nozzle is performed in a state where the water level in the water tank main body is lowered to the swirling flow generating water level and the water level is relatively low and the amount of water is small, a large swirling stirring effect can be obtained. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a plan view showing another embodiment of the water tank main body.

FIG. 5 is a plan view of a comparative example.

FIG. 6 is a sectional view taken along line CC of FIG. 5;

FIG. 7 is a sectional view taken along line DD of FIG. 5;

FIG. 8 is a plan view of a conventional example.

FIG. 9 is a sectional view taken along line EE of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sewage inflow pipe (inflow passage) 2 Water tank main body 2A Bottom member of water tank main body 5 Pump inlet 7 Pre-rotation tank 8A Pre-rotation part 8B Pre-rotation part 9 Inflow path 10 Inflow path 12A Discharge pipe 12B Discharge pipe 15 Branch pipe 16 Swirling flow generating nozzle 17 Water level detecting means 19 Swirling flow generating valve P1 Pump P2 Pump R1 Pump impeller rotation direction R2 Pre-swirling flow rotation direction HWL Pump operation start water level LWL Swirling flow generation water level LWL1 Upper level of pre-swirling tank

Claims (1)

[Claims] At least one pre-swirler for inserting a suction port of a pump at a bottom of a water tank main body to which an inflow passage is connected, and water flowing from the inflow water channel into the water tank main body is tangentially directed to the pre-swirler. A pre-swirl tank provided with an inflow passage for generating a pre-swirl flow that guides the pump in a direction close thereto and turns in the same direction as the rotation direction of the pump impeller in the pre-swirl section. A branch pipe is connected to the discharge pipe, and the swirl flow generating nozzle provided at the tip of the branch pipe is positioned at the upper end level of the pre-swirl tank more than the middle between the upper level of the pre-swirl tank and the operation start water level of the pump. A water level detecting means for detecting the operation start water level and the swirl flow generation water level of the pump is provided while being installed at an angle slightly lower than the horizontal in the same direction as the rotation direction of the pump impeller at the swirl flow generation water level biased to And said When the water level of the water tank main body drops from the pump operation start water level to the swirl flow generating water level by the operation of the pump, the swirl flow generating valve opens for a predetermined time based on the detection of the water level detecting means for detecting the swirl flow generating water level. Is provided in the branch pipe.